P1: Critical Starting a QtEmbedded-4.6.2 application linked against uClibc 0.9.30.1 results in an immediate segmentation fault. This is due to an incompatibility of the uClibc with the standard libc about the "realpath" function. The man of the function clearly specifies that "if resolved path (the second argument) is NULL, then realpath uses malloc to allocate a buffer ...". However, uClibc doesn't support this functionality and issues a warning at compile-time when the function is called with a NULL argument.
A simple patch can correct this problem. It is fully compatible with the uClibc and the stdlibc :
diff -aurp -x '*.o' qt-everywhere-opensource-src-4.6.2-old/src/corelib/io/qfsfileengine.cpp qt-everywhere-opensource-src-4.6.2/src/corelib/io/qfsfileengine.cpp --- qt-everywhere-opensource-src-4.6.2-old/src/corelib/io/qfsfileengine.cpp 2010-02-11 16:55:23.000000000 +0100 +++ qt-everywhere-opensource-src-4.6.2/src/corelib/io/qfsfileengine.cpp 2010-02-19 14:57:06.000000000 +0100 @@ -145,10 +145,9 @@ QString QFSFileEnginePrivate::canonicali #endif // Mac OS X 10.5.x doesn't support the realpath(X,0) extenstion we use here. #if defined(Q_OS_LINUX) || defined(Q_OS_SYMBIAN) - char *ret = realpath(path.toLocal8Bit().constData(), (char*)0); - if (ret) { + char ret[PATH_MAX]; + if (realpath(path.toLocal8Bit().constData(), ret)) { QString canonicalPath = QDir::cleanPath(QString::fromLocal8Bit(ret)); - free(ret); return canonicalPath; } #endif
This bug was not present is Qt-4.5.3, and is present with Qt-4.6.2. It didn't check with intermediate versions.